1. Field of the Invention
This invention relates to remotely activated door hinges. In particular it relates to normally openable hinges which close a door when activated by an electric signal.
2. Discussion of Related Art
Currently, a door which closes off part of a building 15 (such as a fire door), can be fitted with an external closing mechanism attached to the door to control opening and closing of the door. Usually such a mechanism closes an open door; or keeps a door fully open until a signal is received to close it. Lacking such a mechanism, a strategic fire door is usually kept closed at all times.
The present intent was to replace the external activating mechanism with one integral with an existing door hinge. Therefore, a search was undertaken in the U.S. patent literature for door controls and activated hinges. Eight patents were located:    U.S. Pat. No. 294,746 (1884) Lock Hinge    U.S. Pat. No. 853,588 (1907) Door Releasing Mechanism    U.S. Pat. No. 872,680 (1907) Automatic Releaser for Fire Doors    U.S. Pat. No. 1,540,647 (1925) Fire Door Control    U.S. Pat. No. 4,665,584 (1987) Buoyant Valve Member Closing Device for Doors    U.S. Pat. No. 5,408,726 (1995) Locking Device for Locking a Closure in an Open Position    U.S. Pat. No. 5,727,348 (1998) Portable Remote Controlled Door Closer    0111831 (2004) Door Closer (Publication)A review of these patents shows that apart from the 1884 patent, none of the inventions featured an integral hinge control mechanism. A novel design of an integral hinge 10 mechanism was therefore devised, the essentials of which are described in the Brief Summary Of The Invention which follows.